I’d completed my first rebuild of a host from Windows Server 2012 to 2012 R2. I’d put the SCVMM agent etc. back onto it and everything seemed OK.
I then tried to do a Live (VSM) migration of a VM from another host onto the rebuilt one. At the Select Host stage, the rating for the 2012 R2 host took ages to appear, and then showed up with all five stars greyed out and an error showing in the Rating Explanation tab. The error description was as follows:
The VM HVVM01 cannot be migrated to host rcmhvhost01.rcmtech.co.uk due to incompatibility issues. The Virtual Machine Management Service failed to establish a connection for a Virtual Machine migration with host 'rcmhvhost01.rcmtech.co.uk': A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond. (0x8007274C).
I did a quick search and found this page which initially seemed hopeful: I did not have the vmms service (Hyper-V Virtual Machine Management) listening on port 6600. However I could do a refresh of the host via VMM, and I could also connect to the host via Hyper-V Manager. Stopping and restarting the vmms service made no difference though.
Then I checked the Live Migration settings for the host via Hyper-V Manager, and whilst Live Migration was enabled there was a warning:
Incoming live migrations are blocked because no IP addresses are specified. To fix this, add addresses or allow any available network.
Sure enough, of the two radio buttons, the one selected was Use these IP addresses for live migration, however there was no IP address in the box below. I don’t recall having to configure this for my other (2012, not R2) hosts, but checked the setting on one of them and found the other radio button was selected: Use any available network for live migration. So I changed the setting on the 2012 R2 host to that, and the warning went away and now live migration works to the host. I now also have vmms listening on port 6600.
I’ve now added the following line to my PowerShell host configuration script:
Set-SCVMHost -VMHost $VMHost -EnableLiveMigration $true -UseAnyMigrationSubnet $true -LiveMigrationMaximum "2" -LiveStorageMigrationMaximum "2" -MigrationPerformanceOption "UseCompression" -MigrationAuthProtocol "Kerberos"
You’ll notice I’m also configuring some other Live Migration features. These may well be the default settings, but I’m not leaving that to chance after my experience with the Live Migration IP address setting.